Potential antitumor agents. 44. Synthesis and antitumor activity of new classes of diacridines: importance of linker chain rigidity for DNA binding kinetics and biological activity
摘要:
Four classes of diacridines, joined at the 9-position by linker chains of varying length, rigidity, and polarity, were evaluated for DNA-binding properties and antitumor activity. Diacridines linked by flexible chains of varying polarity show relatively fast chromophore exchange kinetics among DNA binding sites but slower dissociation rates, suggesting the potential for considerable "creeping" of the drug along the helix, and are inactive in vivo. The exchange kinetics can be slowed dramatically by inclusion of positive charges in the side chain, but the resulting polycationic drugs are inactive in vivo, possibly due to poor distribution. Diacridines linked by a rigid, polar but neutral dicarbamoylpyrazole chain retain slow exchange kinetics, have a greatly reduced potential "creep rate", and possess good in vitro potency and significant in vivo antileukemic activity.
Potential antitumor agents. 44. Synthesis and antitumor activity of new classes of diacridines: importance of linker chain rigidity for DNA binding kinetics and biological activity
摘要:
Four classes of diacridines, joined at the 9-position by linker chains of varying length, rigidity, and polarity, were evaluated for DNA-binding properties and antitumor activity. Diacridines linked by flexible chains of varying polarity show relatively fast chromophore exchange kinetics among DNA binding sites but slower dissociation rates, suggesting the potential for considerable "creeping" of the drug along the helix, and are inactive in vivo. The exchange kinetics can be slowed dramatically by inclusion of positive charges in the side chain, but the resulting polycationic drugs are inactive in vivo, possibly due to poor distribution. Diacridines linked by a rigid, polar but neutral dicarbamoylpyrazole chain retain slow exchange kinetics, have a greatly reduced potential "creep rate", and possess good in vitro potency and significant in vivo antileukemic activity.
The present invention relates to a nasally administrable composition of a physiologically active cyclic peptide and pharmaceutically acceptable salts thereof that is prepared by homogeneously dispersing a physiologically active cyclic peptide such as antifungal cyclic peptides (aerothricins, echinocandin analogs, pneumocandin analogs, and aureobacidines), antibacterial cyclic peptides (e.g. vancomycin, daptomycin), cyclosporin A, lanreotide, vapreotide, vasopressin antagonist (U.S. Pat. No. 5,095,003) and eptifibatide in unique carrier, i.e. a physiologically acceptable powdery or crystalline carrier containing a water insoluble polyvalent metal carrier, or organic carrier having a mean particle size of 20 to 500 &mgr;m, in the presence or absence of an absorption enhancer and by homogeneously adsorbing onto the carrier, and its use for therapeutic treatment of disease such as systemic fungal infections by intranasal administration.
The composition can be nasally administered in powder form.